Over and above this, the invention relates to a preform for producing a container having a bottle-like shape produced from a thermoplastic material, said preform being provided with a mouth portion and a fixing ring.
The invention additionally relates to an instrument having a holding device for handling workpieces produced from a thermoplastic material, said workpieces having a mouth portion and a fixing ring.
Finally, the invention relates to a method for handling workpieces produced from a thermoplastic material, said workpieces having a mouth portion and a fixing ring.
Such preforms are typically produced in an injection moulding method and are realized from suitable materials, for example PET or PP. To make handling the preforms easier when carrying out a blowing operation, when the blown containers are being transported and when the filling operation is being carried out, corresponding preforms and containers are usually realized with so-called supporting rings. These supporting rings are located in a region between a mouth portion of the container and a shoulder of the container and are usually integrally moulded in one piece on the preform when the injection moulding operation is carried out.
On account of constantly rising raw material prices as well as on account of aesthetic standpoints, efforts have already been made to realize preforms and blow-moulded containers with scaled-down supporting rings or without any supporting rings. However, these types of structures, known for a long time, have not proved to be sufficiently fit for purpose in order to support simple and at the same time reliable handling.